title: Meta-analysis: the significance of screening for JAK2V617F mutation in Budd-Chiari syndrome and portal venous system thrombosis.
abstract: BACKGROUND
  It is important to evaluate whether screening for JAK2V617F mutation should be routinely performed in patients with Budd-Chiari syndrome (BCS) and portal venous system thrombosis (PVST). However, the prevalence of JAK2V617F mutation in such patients is substantially varied, and its association with development of myeloproliferative disorders (MPD) is deficiently identified.
  
  
  OBJECTIVE
  To estimate the prevalence of JAK2V617F mutation and to explore the significance of screening for JAK2V617F mutation in these patients.
  
  
  METHODS
  All observational studies regarding the prevalence of JAK2V617F mutation in patients with BCS and PVST were identified via PubMed and MEDLINE databases. Primary items were the proportions of JAK2V617F mutation and MPD.
  
  
  RESULTS
  Twenty-three studies fulfilled the inclusion criteria. Regardless of underlying aetiological factors, the pooled prevalence of JAK2V617F mutation was 37% and 24% in patients with BCS and PVST respectively. After pre-existing MPD was excluded, the pooled prevalence was decreased to 26% and 19%. Heterogeneity among studies was significant for the prevalence of JAK2V617F mutation. Compared with healthy subjects and patients with thrombosis in other sites, the prevalence of JAKV617F mutation was significantly higher in patients with BCS and PVST. The prevalence of MPD was significantly higher in patients with JAK2V617F mutation than those without.
  
  
  CONCLUSIONS
  JAK2V617F mutation is frequently found in patients with BCS and PVST, but there is a huge variation of prevalence among the included studies. Additionally, it is more specific to thrombosis in splanchnic areas and strongly associated with the development of MPD in these patients. Further studies are needed to evaluate whether the screening test should be widely performed in Asian countries and cirrhotic patients.
authors.affiliation: Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 15 West Changle Road, Xi'an, China.
authors.forename: X
authors.initials: X
authors.lastname: Qi
authors.forename: Z
authors.initials: Z
authors.lastname: Yang
authors.forename: M
authors.initials: M
authors.lastname: Bai
authors.forename: X
authors.initials: X
authors.lastname: Shi
authors.forename: G
authors.initials: G
authors.lastname: Han
authors.forename: D
authors.initials: D
authors.lastname: Fan
mesh_terms: D006502:Budd-Chiari Syndrome / Q000235:genetics*; D005820:Genetic Testing; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D008403:Mass Screening; D009154:Mutation / Q000235:genetics*; D011169:Portal Vein; D020246:Venous Thrombosis / Q000235:genetics*
chemical_list: C507924:JAK2 protein, human; D053614:Janus Kinase 2